“You’re confusing a modern man with an American liberal. An American liberal isn’t necessarily a modern man.” The words date from 1983, spoken by the Jewish-born archbishop of Paris, Cardinal Jean-Marie Lustiger, to a New York Times reporter. They might better serve as an enchiridion for appreciating Pope John Paul II’s relationship to the century in which he was born and bore witness.

In all the ways that we typically understand “modern,” the humble priest from Krakow cut an unlikely modern figure. Notwithstanding his learning and his early experience with Nazism, he languished under the communist shadow in what many in the West regarded as the most backwards branch of the Catholic Church in the world. Among ordinary people he was popular, and had none of the disdain for their favorite saints and folk ceremonies and communal feasts. And, of course, he became a bishop in a land where it was held as an article of science that religion was a relic of the past. Yet it was this man who would challenge the world, a shepherd tracing his authority to a first-century fisherman who would master — as no man in his lifetime matched — all the elements of media to remind us of something we had too often forgotten this century past: what it means to be human.

By the time he took his place on the chair of St. Peter, of course, the economic catastrophe that was communism had long been apparent. Notwithstanding that economic failure, there remained a sense that communism did understand power, a feeling augmented by the uneasy feeling that that communist insurgencies from Asia to Latin America in the end tended to prevail — and cemented by Brezhnev’s famous doctrine that “once communist, always communist.”

Many would have said the same of secularism. Where communism held sway, its harsh rule may have hardened rather than stifled religious resistance. In the West, where people were free to choose or reject, it was another story. Secularization — and the sense that faith was increasingly irrelevant — seemed increasingly attractive and religion correspondingly irrelevant. And nowhere did religion seem less modern than where it came up against the fun and promises of the sexual revolution.

In the end, John Paul did not triumph over these pressures the way he did over Soviet Communism. Yet he did something even more compelling: He challenged secularism’s most debilitating assumptions. In his person, in his writings, in the barbed-wire pastoral cross he carried, he confounded his critics by insisting that the God-given dignity of the human person must be front and foremost.

He did this in the first moments of his papacy, when he appeared on the loggia of St. Peter’s Basilica and set that magnificent Polish jaw against the prevailing winds. “Be not afraid,” he told us, and when they saw he wasn’t afraid, people took heart.

He did this on his first visit to his beloved Poland as pope. “Let thy spirit descend and renew this holy land, this land!” the new Pope told his fellow Poles on Warsaw’s Victory Square. When the Berlin Wall came down 10 years later, it was in good part because John Paul II had exposed the many lies about the human person that had kept it propped up.

He did this also on his trips to the more affluent parts of the world, like America. You didn’t need Madison Avenue to tell you that “Pick up your cross” is going to be a much harder sell than “Do what makes you feel good.”

Yet it was this man who attracted immense crowds to World Youth Day in Denver, where a half million people turned out. He told them: “The challenge is to make the Church’s Yes to life concrete and effective. The struggle will be long, and it needs each one of you. Place your intelligence, your talents, your enthusiasm, your compassion and your fortitude at the service of life!”

That vision would reach its apex in the seminal contribution of his papacy: the encyclical Evangelium Vitae. In many ways, it expressed the heart of John Paul’s vision: that the Gospel is life itself. Even those who could not follow all the arguments understood the powerful new terms he introduced into our world’s vocabulary: “the culture of life” and the “culture of death.”

And then a funny thing happened. People responded. The culture of death was something people understood, maybe especially the people who were part of it. Instead of the “No” they were accustomed to, this pope became what his main biographer, George Weigel, called “a witness to hope.” And the world saw that it was real — in the lit-up face of a handicapped girl that he touched, in the happy tears of the mother of a son with Down syndrome whom he met, in the sick and old whom he came and saw and loved. The message and the man were one.

The “Yes” to life and the freedom we find in Christ. At the heart of John Paul’s modernity was his understanding that none of the “isms” heralded as the key to happiness — communism, capitalism, sexual liberation, abortion — could offer people what modernity so often leaves them wanting: the simple surety that we are loved. In his life, Pope John Paul II confounded his critics more than he persuaded them. By the time he went home to the Lord, however, even they found themselves answering on what were largely his terms.

Bill McGurn was the chief speechwriter for President George W. Bush from June 2006 until February 2008. He now writes “Main Street” at the Wall Street Journal.